Pollutant Concentrations

Air quality readings will be available hourly from 7am to 11pm. Air quality readings from 12am to 6am will be made available at 7am on the same day.

Readings on 04 Jan 2015

View reading for:

Region

24-hr Sulphur dioxide(µg/m3)

24-hr PM10(µg/m3)

1-hr Nitrogen dioxide(µg/m3)a

8-hr Ozone(µg/m3)

8-hr Carbon monoxide(mg/m3)

24-hr PM2.5(µg/m3)

North

9(6)

20(20)

10(-)

37(16)

0.6(6)

10(41)

South

6(4)

19(19)

18(-)

42(18)

0.3(3)

10(41)

East

8(5)

20(20)

12(-)

44(18)

0.3(3)

11(44)

West

3(2)

20(20)

9(-)

44(19)

0.4(4)

10(40)

Central

5(3)

19(19)

13(-)

45(19)

0.2(2)

9(37)

1-hr PM2.5 (µg/m3)b Readings on 04 Jan 2015

View reading for:

Time

1am

2am

3am

4am

5am

6am

7am

8am

9am

10am

11am

12pm

North

14

13

12

10

10

11

11

9

7

5

15

15

South

8

9

8

10

10

9

12

6

11

8

13

13

East

11

10

12

12

12

11

11

10

10

11

10

17

West

9

7

9

10

6

10

7

8

10

10

18

16

Central

7

8

9

9

7

10

13

10

9

9

8

13

Time

1pm

2pm

3pm

4pm

5pm

6pm

7pm

8pm

9pm

10pm

11pm

12am

North

7

8

6

7

13

7

6

6

9

12

11

-

South

14

15

12

10

11

5

8

9

7

6

10

-

East

12

9

9

7

8

8

12

8

10

10

10

-

West

16

15

12

12

7

7

8

3

6

9

7

-

Central

11

11

9

5

7

9

9

9

6

10

7

-

Note:a Sub-index for nitrogen dioxide is reported only when the 1-hr concentration equals or exceeds 1130 µg/m3.

b There is no sub-index for 1-hr PM2.5.

3-hr PSI Readings from 1am to 12am on
04 Jan 2015

Time

1am

2am

3am

4am

5am

6am

7am

8am

9am

10am

11am

12pm

3-hr PSI

44

41

40

41

41

41

42

41

40

38

43

51

Time

1pm

2pm

3pm

4pm

5pm

6pm

7pm

8pm

9pm

10pm

11pm

12am

3-hr PSI

52

52

46

41

38

34

35

31

32

33

36

-

Hourly updates of 3-hr PSI readings are provided from 7am to 11pm. The 3-hr PSI readings from 12am to 6am will be made available at 7am on the same day. The 3-hr PSI readings are calculated based on PM2.5 concentrations only.